There are known various types of three-dimensional image display apparatuses capable of displaying moving picture image, that is, three-dimensional displays. In recent years, a three-dimensional display, particularly of a flat panel type, has been desired to be developed which requires no dedicated glasses or the like. Some three-dimensional image display apparatuses of a type requiring no dedicated glasses are configured such that a light ray control element is installed immediately before a display panel (display apparatus) with fixed pixel positions, such as a direct-view liquid crystal display apparatus, a projection liquid crystal display apparatus or plasma display apparatus, so as to controllably direct the emission of light rays from the display panel toward an observer.
The light ray control element according to this scheme has a function to control light rays so that even when looking at the same position on the light ray control element, the observer views different picture images depending on the angle at which the observer looks at the light ray control element. Specifically, an array of slits (parallax barrier) or an array of lenticular lenses (lenticular sheet) is used as a light ray control element to apply only lateral parallaxes (what is called horizontal parallaxes). A pin hole array or a lens array is used as a light ray control element to apply not only horizontal parallaxes but also up-down parallaxes (vertical parallaxes).
The apparatuses for three-dimensional displays using a light ray control element are further classified into a binocular type, a multi-view type, a super multi-view type (super multi-view conditions for the multi-view type), an integral imaging type (hereinafter sometimes simply referred to as the II type), and the like. In the binocular type, at a preset observation position (viewpoint position), both eyes are subjected to binocular parallaxes for stereoscopic viewing. In the multi-view type, the super-multi-view type, or the like (hereinafter simply referred to as the multi-view type), a plurality of viewpoint positions are used to increase a visible range and to make side surfaces visible (to provide motion parallaxes). The II type display apparatus, invented about 100 years ago, is based on the principle of integral photography (IP) applied to three-dimensional photographs. A three-dimensional image display apparatus of the II type is known from Japanese Patent No. 3892808. Three-dimensional picture images (picture images) observed using the multi-view or II type more or less involve motion parallaxes and are referred to as three-dimensional picture images distinctively from binocular type stereoscopic picture images.
A three-dimensional image display apparatus with a combination of a light ray control element and a flat display device generally adopts a technique to design the apparatus with an assumed viewpoint position. However, the technique to design the apparatus with the assumed viewpoint position disadvantageously limits the viewpoint position. Furthermore, a technique to design the apparatus with no assumed viewpoint position disadvantageously slightly narrows a viewing space. Thus, there has been a desire to improve display images so as to eliminate the restraint on the viewpoint position and to maximize the viewing space.